Polyaromatic ether‐ketones and polyaromatic ether‐ketone sulfonamides from 4‐phenoxybenzoyl chloride and from 4,4′‐dichloroformyldiphenyl ether

Polyaromatic ether‐ketones possessing high thermal stabilities were prepared by Friedel—Crafts polymerizations from 4‐phenoxybenzoyl chloride and from 4,4′‐dichloroformyldiphenyl ether and diphenyl ether. Sulfonation and subsequent sulfamidation of these polymers afforded polyaromatic ether‐ketone sulfonamides with different degrees of substitution depending on the reaction conditions. Sulfonation reactions with chlorosulfonic acid did not cause much degradation on the polymers. The polysulfonamides were soluble in various organic solvents such as N,N ‐dimethylformamide, dimethylsulfoxide, or chloroform, and could be cast into transparent films. These polymers may be used as desalination membranes.